JPS6227347Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a backing device that is incorporated into a laser welding machine for cutting and welding steel plates. When laser welding is performed by adjusting the position of the beam focus, a back bar with a structure suitable for this adjustment, that is, a back bar with grooves formed on its surface (hereinafter simply referred to as a grooved back bar), and a back bar with grooves formed on the surface are used. The present invention relates to a backing device that allows easy use of a back bar without grooves (hereinafter simply referred to as a back bar without grooves).

Recently, laser butt welding has been used to connect a leading steel strip (hereinafter referred to as the preceding material) and a trailing steel strip (hereinafter referred to as the trailing material) in a continuous processing and manufacturing line for steel plates. This welding involves cutting the opposing ends of the leading and trailing plates using laser cutting, mechanical cutting, etc., and then butting each cut end surface to form a butt groove line. A laser torch is run along the groove line, and the laser beam melts the groove line and performs laser welding.

For example, FIGS. 1a, b, c, and d are explanatory diagrams of each step of the conventional laser welding method. First, as shown in FIG. Clamps 1 and 2 on the input and output sides, respectively.
Then, for example, the upper blade 3 of the double shear is lowered, and the opposing ends of the leading and trailing plates 5 and 6 are simultaneously cut between the upper blade 3 and the lower blade 4 (see Fig. 1b). ), forming a cut end surface. Next, after raising the upper blade 3 and lowering the lower blade 4, this double cut shear is retracted off-line as shown in Figure 1c, and the entry clamp 1 is advanced by the cutting interval as shown in Figure 1d. Then, the cut ends of the leading and trailing plates 5 and 6 are butted against each other to form a groove, and the laser torch 7 is run in the width direction of the plates along this butt groove line to perform laser welding (see Figure 1 d). ).

This laser welding is said to be suitable for welding thin plates such as silicon steel plates because the spot diameter of the laser beam can be reduced to, for example, about 0.1 mm to increase the energy density and reduce the width of the heat affected zone.
However, if the spot diameter is extremely small and there is a slight gap locally in the width direction of the groove, the laser beam will penetrate the groove from the gap and cause welding defects, etc. thickness
It appears prominently on thin plates of 0.4 mm or less. For this reason, when the plate thickness is 0.4 mm or more, the beam focus is kept near the surface of the steel plate to maximize the energy density, the welding speed is increased, and sufficient penetration is ensured for welding. Form a Uranami bead. During this thickness welding, the laser beam passes through to the back side and melts the surface of the back bar that is applied to the back side, so a grooved back bar with grooves formed in the part corresponding to this part of the back bar is used.

On the other hand, if the plate is thin, such as 0.4 mm or less, butting must be performed with even stricter precision. However, even when butting is performed with high precision, gaps inevitably remain, and the beam diameter is expanded by keeping the beam focus above or below the steel plate surface to widen the melting range and sequentially pass the groove from the front surface to the back surface. It is melted and laser welded. For this reason, if there are grooves on the surface of the back bar, molten metal will fall into the grooves, and when welding thin plates, it is necessary to use a back bar without grooves on the surface.

Therefore, if we look at the range of sheet thickness that must be processed on a normal cold rolling factory line, it is extremely wide, from 0.2 to 3.2 mm, and the range of sheet width is also wide, from 508 to 1270 mm. It is necessary to use the back bar differently depending on the thickness of the plate.
In particular, since a backing device that can use two types of back bars depending on the plate thickness has not yet been proposed, it is extremely difficult to perform stable laser welding on a wide range of plate thicknesses on one line.

The purpose of the present invention is to solve the above-mentioned drawbacks. Specifically, the present invention aims to solve the above-mentioned drawbacks. Specifically, the present invention is a backing material that can use individually attached grooved back bars and non-grooved back bars depending on the thickness of the preceding and succeeding materials to be welded. Suggest a device.

Embodiments of the present invention will be described below with reference to the drawings.

Note that FIG. 2 is a front view of a steel plate cutting/welding line in which a backing device according to one embodiment of the present invention is incorporated into a laser welding machine, and FIG. 4 is a front view of the backing device shown in FIG. 2; FIG. 4 is a plan view of the backing device shown in FIG. 2;

First, in FIGS. 2 and 3, reference numeral 1
0 indicates an entry side clamp, 11 an exit side clamp, 12 an upper blade, 13 a lower blade, 14 a leading plate, and 15 a trailing plate. Prior to laser welding, the leading and trailing plates 14, 1
The cutting device for cutting the opposite end of the blade 5 is composed of an upper blade 12 and a lower blade 13 that can be raised and lowered, and is configured so that it can be retreated off-line after cutting.

Further, after the cutting device is evacuated, the leading and trailing plates 14,
A laser torch 25 is provided on the No. 15 width clamp so as to be movable, and a laser transmitter (not shown) or the like is connected to the laser torch 25 to constitute a laser welding machine.

This laser welding machine, especially the laser torch 25
A pair of swing arm devices 16 and 17 are provided on both sides. Since these devices have the same structure, only one will be shown below, but one of the rotating arm devices 1
7 is attached with a grooved back bar 18a as described later, and the other swing arm device 16 is attached with a grooveless back bar 18b.

That is, one swing arm device 17 includes a pair of swing arms 19a, a shaft 20a, and a rotating cylinder 23.
A grooved back bar 18a is attached to the tips of a pair of swing arms 19a. This grooved back bar 18a has grooves 24 as shown in FIG.
form. A grooved back bar 18a is attached to the tips of the pair of swing arms 19a.
The rear end of each swing arm 19a is fixed to the shaft 20a with a key or the like. This shaft 20a is rotatably supported by a bearing 27, and a gear 21a is disposed approximately in the center of the shaft 20a.
The gear 21a is connected to the rotating cylinder 23a via the gear 23a. Therefore, when the rotating cylinder 23a is rotated, the rotating arm 19a
rotates around the shaft 20a, and the grooved back bar 18a at the tip abuts against the butting grooves of the leading and trailing plates 14 and 15 from the back side thereof, and functions as a backing metal during laser welding.

Further, the other rotating arm device 16 is also different from the one rotating arm device 17 except that a grooveless back bar 18b is attached to the tip of the pair of rotating arms 19b.
It is configured in the same way. That is, the pair of swing arms 19b are configured to be able to swing around the shaft 20b by the rotation cylinder 23b, and the grooveless back bar 18b can be brought into contact with the butt groove between the leading and trailing plates 14 and 15 from the back side. do it like this.

Therefore, the effects of the backing device of the present invention constructed as described above will be explained below through a case where it is incorporated into a laser welding machine of a laser welding line for cutting steel plates.

First, prior to welding, the leading and trailing plates 14 and 15 are clamped at predetermined positions using both the inlet and outlet clamps 10 and 11, as shown in FIG. 2, and then the upper blade 12 of the cutting device is lowered. , the opposing ends of the leading and trailing plates 14 and 15 are cut simultaneously. After cutting, use upper blade 1
2 is raised and the lower blade 13 is lowered to move the cutting device offline, and then the entry side clamp 10 is advanced and the cutting ends of the leading and trailing plates 14 and 15 are brought together to form a butt bevel 28. Form.

Next, during welding, if the plate thickness is 0.4 mm or more, a grooved back bar 18a will be used. As shown in FIG. 3, the butt groove 28 is aligned approximately with the center of the groove 24. In this state, when welding is performed by moving the laser torch 25 in the width direction and keeping the focus of the laser beam on the surfaces of the leading and trailing plates 14 and 15, sufficient penetration and a good underwave bead can be obtained.

Also, if the plate thickness is 0.4 mm or less, there is no groove back bar 1.
8b, the rotating cylinder 23a of the other rotating arm device 16 is driven to rotate the grooveless back bar 18b so that it comes into contact with the back surface of the butt groove, and the focus of the laser beam is focused on the leading and trailing plates 14,
Welding is carried out by keeping it slightly above the surface of 15.

In summary, the present invention provides a pair of rotating arm devices sandwiching the laser torch of a laser welding machine.
Since it consists of a grooved back bar attached to one rotating arm device and a non-grooved back bar attached to the other rotating arm device, it is possible to perform laser welding that is mainly suited to the plate thickness on one steel plate cutting/welding line. .

[Brief explanation of the drawing]

Figures 1a, b, c, and d are explanatory diagrams of each process of the conventional laser welding method, and Figure 2 is an illustration of a steel plate in which a backing device according to an embodiment of the present invention is incorporated into a laser welding machine. FIG. 3 is a front view of the cutting/welding device, FIG. 3 is a front view of the backing device after the cutting device has been evacuated from the line, and FIG. 4 is a plan view of the backing device shown in FIG. 2. Code, 1... Entry side clamp, 2... Output side clamp, 3... Upper blade, 4... Lower blade, 5... Leading plate, 6
... Trailing plate, 7 ... Laser torch, 10 ... Entry side clamp, 11 ... Output side clamp, 12 ... Upper blade, 13 ... Lower blade, 14 ... Leading plate, 15 ... Trailing plate, 16, 17...Swivel arm device, 18a...
... Back bar with groove, 18b... Back bar without groove, 19a, 19b... Swivel arm, 20a, 2
0b...shaft, 21a...gear, 22a...gear,
23a, 23b...Rotating cylinder, 24...Groove,
25... Laser torch, 27... Bearing.

Claims (1)

[Scope of utility model registration request] The welding torch of the welding machine that performs laser welding is used on a steel plate cutting and welding line that cuts the opposing ends of the leading steel plate and the trailing steel plate, butts the cut end faces, and laser welds the butt grooves. Swivel arm devices each having the same structure and rotating arms pivoting around the rear end are provided on both sides, and a leading steel plate and a rear steel plate are installed at the tip of the swing arm of one of these swing arm devices. Attach a grooved back bar that comes into contact with the butt groove between each cut end surface of the row steel plate from the back side and has a groove formed on the surface so as to correspond to the butt groove in this abutting state, and then install the grooved back bar on the other side. A laser for a steel plate cutting/welding line, characterized in that a grooveless back bar that abuts the butt groove from the back side and has no grooves formed on the surface is attached to the tip of the rotating arm of the rotating arm device. A backing device built into a welding machine.